Jones was doing what has become his ritual before a fight ... he was meditating at a park in Patterson, NJ when he heard a woman scream, "I've been robbed!"

Jones began chasing the man for a good distance. When the fighter caught up with the alleged robber, he knocked the guy's legs out from under him, then placed him in a figure-four leg lock until Paterson cops arrived.

Jones' fight tonight -- UFC 128 -- is in Newark.

Jones tells TMZ, "It was a great pre-fight warm-up for me!"

read entire article...

video courtesy of Tracy Lee...

# I turned the jets on....we caught the guy. We got the lady's gps back

# then I threw my phone down and went with my coaches. Before you know it, we're sprinting up a steep hill chasing after him.

# right away....Coach Wink goes after this guy. Without hesitation, Coach Jackson went after him...I was shocked and stood there for a second

# So while we were at the park today a crack head smashed this old ladys car window and took off running with her (cont) http://tl.gd/9cbc6m

more of Jon Jone's Official Twitter...

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